Intracluster and Intragroup Entropy from Quasar Activity

Lapi, A.; Cavaliere, A.; Menci, Nicola

doi:10.1086/426376

Cited by 88 publications

(180 citation statements)

References 63 publications

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“…The total kinetic power of the out-flowing gas is 1.2 × 10 44 erg s −1 (assuming an outflow rate of 700 km s −1 ), which corresponds to a few percent of the AGN bolometric luminosity, L Bol ∼ 5 × 10 45 erg s −1 (Lonsdale et al 2003) which, for a black hole mass of ∼6 × 10 8 M (Tacconi et al 2002), corresponds to 6% of the Eddington luminosity. This value of the kinetic energy is very close to that expected for a shock wave produced by radiation pressure onto the interstellar medium (Lapi et al 2005). The corresponding energy injected into the interstellar medium is ΔE ∼ f × L Bol × t AGN ∼ 5.5 × 10 57 erg, at least 4 orders of magnitude higher than the overall contribution of supernovae inferred from the observed stellar mass and age of Mrk 231 (Davies et al 2004), and even larger than the energy injected by the radio jets (Lonsdale et al 2003).…”

Section: Discussionsupporting

confidence: 78%

Quasar feedback revealed by giant molecular outflows

Feruglio¹,

Maiolino²,

Piconcelli³

et al. 2010

A&A

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608

699

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In the standard scenario for galaxy evolution young star-forming galaxies transform into red bulge-dominated spheroids, where star formation has been quenched. To explain this transformation, a strong negative feedback generated by accretion onto a central supermassive black hole is often invoked. The depletion of gas resulting from quasar-driven outflows should eventually stop star-formation across the host galaxy and lead the black hole to "suicide" by starvation. Direct observational evidence for a major quasar feedback onto the host galaxy is still missing, because outflows previously observed in quasars are generally associated with the ionized component of the gas, which only accounts for a minor fraction of the total gas content, and typically occurrs in the central regions. We used the IRAM PdB Interferometer to observe the CO(1−0) transition in Mrk 231, the closest quasar known. Thanks to the wide band we detected broad wings of the CO line, with velocities of up to 750 km s −1 and spatially resolved on the kpc scale. These broad CO wings trace a giant molecular outflow of about 700 M /year, far larger than the ongoing star-formation rate (∼200 M /year) observed in the host galaxy. This wind will totally expel the cold gas reservoir in Mrk 231 in about 10 7 yrs, therefore halting the starformation activity on the same timescale. The inferred kinetic energy in the molecular outflow is ∼1.2 × 10 44 erg/s, corresponding to a few percent of the AGN bolometric luminosity, which is very close to the fraction expected by models ascribing quasar feedback to highly supersonic shocks generated by radiatively accelerated nuclear winds. Instead, the contribution by the SNe associated with the starburst fall short by several orders of magnitude to account for the kinetic energy observed in the outflow. The direct observational evidence for quasar feedback reported here provides solid support to the scenarios ascribing the observed properties of local massive galaxies to quasar-induced large-scale winds.

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Section: Discussionsupporting

confidence: 78%

Quasar feedback revealed by giant molecular outflows

Feruglio¹,

Maiolino²,

Piconcelli³

et al. 2010

A&A

Self Cite

608

699

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“…In this SAM, the AGN timescale, as well as both the AGN SMBH masses and Eddington ratios, are not free parameters, but are calculated self-consistently (the model only assumes that the accretion can proceed at most at the Eddington limit). The SAM includes a rather detailed treatment of AGN "quasar mode" feedback (Menci et al 2008), in terms of a blast wave carrying the AGN power outwards (Lapi et al 2005). The SAM predicts the comuving densities of all AGN, which are either unobscured, moderately obscured, or Compton thick.…”

Section: Discussionmentioning

confidence: 99%

Faint high-redshift AGN in theChandradeep field south: the evolution of the AGN luminosity function and black hole demography

Fiore

Puccetti²,

Grazian

et al. 2011

A&A

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157

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Context. We present detection and analysis of faint X-ray sources in the Chandra deep field south (CDFS) using the 4 Ms Chandra observation. Aims. We place constraints on active galactic nuclei (AGN) luminosity functions at z = 3-7, its cosmological evolution, and highredshift black hole and AGN demography. Methods. We use a new detection algorithm, using the entire three-dimensional data-cube (position and energy), and searching for X-ray counts at the position of high-z galaxies in the GOODS-South survey.Results. This optimized technique results in the identification of 54 AGN at z > 3, 29 of which are new detections. Applying stringent completeness criteria, we derive AGN luminosity functions in the redshift bins 3-4, 4-5, and >5.8 and for 42.75 < log L(2-10 keV) < 44.5. We combine this data with the luminous AGN luminosity functions from optical surveys and find that the evolution of the high-z, wide luminosity range luminosity function can be modeled by pure luminosity evolution with L * decreasing from 6.6 × 10 44 erg/s at z = 3 to L * = 2 × 10 44 erg/s at z = 6. We compare the high-z luminosity function with the predictions of theoretical models using galaxy interactions as AGN triggering mechanism. We find that these models are broadly able to reproduce the high-z AGN luminosity functions. Closer agreement is found when we assume a minimum dark matter halo mass for black hole formation and growth. We compare our AGN luminosity functions with galaxy mass functions to derive the high-z AGN duty cycle, using observed Eddington ratio distributions to derive black hole masses. We find that the duty cycle increases with galaxy stellar mass and redshift by a factor of 10-30 from z = 0.25 to z = 4-5. We also report the detection of a large fraction of highly obscured, Compton thick AGN at z > 3 (18 +17 −10 %). Their optical counterparts do not show any reddening and we thus conclude that the size of the X-ray absorber is likely smaller than the dust sublimation radius. We finally report the discovery of a highly star-forming galaxy at z = 3.47, arguing that its X-ray luminosity is likely dominated by stellar sources. If confirmed, this would be one of the farthest objects in which stellar sources have been detected in X-rays.

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“…We recall (see Appendix B in Lapi et al 2005) that the Rankine-Hugoniot conservation conditions for a standing shock give the postshock temperatures and densities in the form…”

Section: Weakening Shocks and Entropy Demisementioning

confidence: 99%

“…At the other end, much entropy is continuously produced at the virial boundary. There the ICP is shocked by the supersonic gravitational inflow of gas accreted from the environment along with the DM (see Tozzi & Norman 2001;Voit 2005;Lapi et al 2005), and is adiabatically stratified into the DM potential well.…”

Section: Introductionmentioning

confidence: 99%

Nonthermal support for the outer intracluster medium

Cavaliere

Lapi

Fusco-Femiano

2010

A&A

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We submit that nonthermalized support for the outer intracluster medium in relaxed galaxy clusters is provided by turbulence, which is driven by inflows of intergalactic gas across the virial accretion shocks. We expect this component to increase briskly during the cluster development for z < ∼ 1/2, owing to three factors. First, the accretion rates of gas and dark matter subside when they feed on the outer wings of the initial perturbations in the accelerating Universe. Second, the infall speeds decrease across the progressively shallower gravitational potential at the shock position. Third, the shocks eventually weaken and leave less thermal energy to feed the intracluster entropy, but relatively more bulk energy to drive turbulence into the outskirts. The overall outcome from these factors is physically modeled and analytically computed; thus we ascertain how these concur in setting the equilibrium of the outer intracluster medium, and predict how the observables in X-rays and μwaves are affected, so as to probe the development of outer turbulence over wide cluster samples. By the same token, we quantify the resulting negative bias to be expected in the total mass evaluated from X-ray measurements.

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Intracluster and Intragroup Entropy from Quasar Activity

Cited by 88 publications

References 63 publications

Quasar feedback revealed by giant molecular outflows

Quasar feedback revealed by giant molecular outflows

Faint high-redshift AGN in theChandradeep field south: the evolution of the AGN luminosity function and black hole demography

Nonthermal support for the outer intracluster medium

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